Conventional processes utilized to form features in a substrate, for example, high aspect ratio features, typically include the use of a polymer forming gas (e.g., carbon tetrafluoride (CF4)) in combination with a provision of a pulsed bias power. However the inventors have observed that such processes typically do not provide sufficient control over the dimensions of the features formed, resulting in non-uniform feature profiles.
Therefore, the inventors have provided improved methods for forming features in a silicon containing layer